There are several types of electric field-driven particles. One class is the so-called electrophoretic particle that is based on the principle of movement of charged particles in an electric field. In an electrophoretic receiver, the charged particles containing different optical densities can be moved by an electric field to or away from the viewing side of the receiver, which produces a contrast in the optical density. Another class of electric field-driven particles are particles carrying an electric dipole. Each pole of the particle is associated with a different optical densities (bi-chromatic). The electric dipole can be aligned by a pair of electrodes in two directions, which orient each of the two polar surfaces to the viewing direction. The different optical densities on the two halves of the particles thus produces a contrast in the optical densities. The receivers typically have a substrate for supporting the imaging layer that contains the field-driven particles. The substrate can be in the range of 75-750 .mu.m in thickness.
The image pixels in the above described receivers are formed by varying the electric field applied to the field-driven particles at each pixel. The electric fields can be produced by applying an electric voltage between a pair of electrodes across the two surfaces of the receiver to drive field-driven particles at that pixel. One difficulty in achieving high-quality images in such receivers is caused by the limited strength of the electric field. For a field strength of an electric field across the receiver, the electric potential across the pair of electrodes is proportional to the thickness of the receiver. High driving voltages are thus needed for driving the field-driven particles for the thick receivers, which requires more complex and expensive driver electronics, as well as more power consumption.
Another difficulty in achieving high quality images on such receivers is caused by the receiver material thickness. The thickness of the receiver material limits the minimum separation between the electrodes in each pair. The separation between the electrodes limits the maximum image resolution achievable on the receiver.